package com.zhy.learning.demo.domain2;

public abstract class F extends D {

    public F() {
        System.out.println("F constructor");
    }

    @Override
    public void beforeStudy() {
        System.out.println("F beforeStudy");
    }

    @Override
    public String afterStudy() {
        System.out.println("F afterStudy");
        return "F";
    }
}
